An efficient and economic kapok/cellulose aerogel for waste oil treatment was successfully fabricated via simple freeze-drying and surface modification. To investigate their oil absorption performance, various aerogels by multi-scale cellulose and different lengths of kapok fibers were characterized. The use of cellulose nanofibers (CNF) enabled aerogels to possess remarkably uniform pore size and structural integrity, while the introduction of kapok improved their mechanical property, oil absorption and retention performance. For kapok/microfibrillated cellulose (MFC) aerogels, an excessively enlarged porous structure caused by long fibers would damage the structural stability of aerogels and reduce their oil absorption capability. Compared with the sheet-like structure formed by self-aggregated MFC, filamentous CNF exhibited better entanglement characteristics and possessed a more positive impact on enhancing the structural integrity and mechanical properties of aerogels. These aerogels presented ultra-low density (4.9 mg/cm³), desirable hydrophobicity (147.6°), outstanding oil absorption (141.9 g/g) and retention (97.7 %) capacity, and excellent selective sorption property, making them ideal absorbents for oil spill cleaning.

通过简单的冷冻干燥和表面改性成功地制备了一种用于废油处理的高效、经济的木棉/纤维素气凝胶。为了研究它们的吸油性能，对由多尺度纤维素和不同长度的木棉纤维制成的各种气凝胶进行了表征。纤维素纳米纤维 (CNF) 的使用使气凝胶具有非常均匀的孔径和结构完整性，而木棉的引入改善了它们的机械性能、吸油和保水性能。对于木棉/微纤化纤维素（MFC）气凝胶，长纤维引起的过度扩大的多孔结构会破坏气凝胶的结构稳定性并降低其吸油能力。与自聚集 MFC 形成的片状结构相比，丝状CNF表现出更好的缠结特性，对增强气凝胶的结构完整性和机械性能具有更积极的影响。这些气凝胶呈现出超低密度（4.9 mg/cm³ )、理想的疏水性 (147.6°)、出色的吸油量 (141.9 g/g) 和截留量 (97.7 %) 以及优异的选择性吸附性能，使其成为清洁溢油的理想吸收剂。